Copper(II) Triflate Catalyzed Amination and Aziridination of 2-Alkyl Substituted 1,3-Dicarbonyl Compounds

A method to prepare α-acyl-β-amino acid and 2,2-diacyl aziridine derivatives efficiently from Cu­(OTf)2 + 1,10-phenanthroline (1,10-phen)-catalyzed amination and aziridination of 2-alkyl substituted 1,3-dicarbonyl compounds with PhINTs is described. By taking advantage of the orthogonal modes of reactivity of the substrate through slight modification of the reaction conditions, a divergence in product selectivity was observed. In the presence of 1.2 equiv of the iminoiodane, amination of the allylic CH bond of the enolic form of the substrate, formed in situ through coordination to the Lewis acidic metal catalyst, was found to selectively occur and give the β-aminated adduct. On the other hand, increasing the amount of the nitrogen source from 1.2 to 2–3 equiv was discovered to result in preferential formal aziridination of the CC bond of the 2-alkyl substituent of the starting material and formation of the aziridine product.

本文报道了一种可高效制备α-酰基-β-氨基酸与2,2-二酰基氮丙啶衍生物的方法：以三氟甲磺酸铜(II)（Cu(OTf)₂）与1,10-邻菲啰啉（1,10-phenanthroline）为催化体系，实现2-烷基取代1,3-二羰基化合物与N-对甲苯磺酰亚胺碘苯（PhI=NTs）的胺化及氮丙啶化反应。通过微调反应条件，利用底物的正交反应活性模式，可实现产物选择性的发散调控：当使用1.2当量的亚胺碘烷试剂时，底物经路易斯酸性金属催化剂配位后原位生成的烯醇式中间体，其烯丙基C-H键会优先发生胺化反应，选择性得到β-氨基化加成产物；反之，当将氮源用量从1.2当量提升至2~3当量时，反应会优先发生原料2-烷基取代基的C-C键形式氮丙啶化，最终生成氮丙啶类产物。